That is a tough question to answer. So far they have been getting the
job done, but appear to be getting overworked lately.
The reason it is a tough question, is that the reason debian-admin stays
out of the limelight is that they are the real power behind the throne.
Without them, Debian cannot exist.
In every large Free Software project I've been on, there were always
power seekers with a modicum of programming skill who were drawn in like
moths to the cupboard. They are more focussed on personal power than on
the future good of the project. They want reputation through popularity
rather than through work.
Making the debian-admin team more open would make it a much larger and
more tempting target for those types. Minimizing your exposure is a
valid security principle. For the good of the project, we need some way
to let the sysadmin team do their jobs without being distracted by
politics.
I don't have the answer of how to accomplish that. But I'd like you to
keep it in mind next time you wonder why they aren't more open.

2.) Would you encourage debian-admin to do so? If yes, how?

Better and faster communication is always important; if they need
assistants, we should encourage them to add people to the team. But
then it becomes a matter of weeding out the powerseekers. Our admin
team is only human; all it takes is one brown-noser to slip in, and
he'll hold open the gates for all the other popularity seekers until the
original hardworking, competent DSA resign in disgust.
Maybe that has already happened. I don't know. It is all so secretive.

3.) Do you think more DSA are needed?

As someone who isn't on the team, and only sees peoples complaints about
poor communication, it does seem like more DSA are needed. As DPL I'd
ask them directly what how they feel about that.
Ted
--

It's not true unless it makes you laugh,
but you don't understand it until it makes you weep.